What does the term sexually transmitted infections include?
Both symptomatic and asymptomatic cases, where sexual activity is the principle mode of transmission
What does the term sexually transmitted disease include?
Symptomatic cases only
Give two examples of infections where sexual activity is a possible mode of transmission, but also have other routes of transmission?
- Sexual transmission of intestinal pathogens
What intestinal pathogens can be transmitted sexually?
What groups are at risk of sexually transmitted infections?
- Young people
- Certain ethnic groups
- Low socio-economic status groups
Why are young people at an increased risk of STIs?
Because they are more sexually active
What do the groups at risk of STIs relate to?
Specific aspects of sexual behaviour
What specific aspects of sexual behaviour can cause an increased risk of STIs?
- Age at first sexual intercourse
- Number of partners
- Sexual orientation
- Unsafe sexual activity
What is happening to the incidence of STIs?
It is increasing
Why may the incidence of STIs be increasing?
- Increased transmission
- Increased GUM attendence
- Improved diagnostic methods, including screening programmes
Why may there be an increased transmission of STIs?
- Changing sexual and social behaviour
- Increased density and mobility of populations
Why may increased GUM attendance give the impression that the incidence of STIs is increasing?
Leads to more diagnoses being made
Why is GUM attendance increasing?
- Decreased stigma
- Greater public, medical, and national awareness
How have diagnostic methods improved regarding STIs?
Better equipment makes it easier to detect organisms
What factors contribute to the burden of STIs?
- Can be both acute and chronic/replapsing infections
- May be consequent pathologies
- Disseminated infectins
- Transmission to fetus/neonate
What does stigma regarding STIs have an impact on?
What consequent pathologies can arise from STIs?
- Pelvic inflammatory disease and infertility
- Reproductive tract cancers
Which STI in particular can cause reproductive tract cancers?
What do disseminated STIs involve?
Multiple organ systems, over years and decades
How can STIs be diagnosed?
- Patients present with genital lesions/problems to GP or GUM clinic
- Clinician notes non-genital clinical features suggestive of STI
- Asymptomatic cases may be detected with contact tracing or screening
What genital problems may a patient present to a GP or GUM clinic with?
- Urethral discharge or pain
- Vaginal discharge
When may a clinical note non-genital clinical features that are suggestive of STI?
If there are clues from the history
What may non-genital clinical features of an STI suggest?
What does contact tracing and screening for STIs look for?
High risk people
What is the purpose of identifying asymptomatic cases by contact tracing and screening?
Reduce risk of complications and transmission
How are STIs managed?
- Treatment with antibiotics
- Contact tracing
What is preferable when giving antibiotics in STIs?
- Single dose or short course
- Delivered at time of diagnosis
- Oral drug
Are co-infections common with STIs?
What is it important to do due to the fact that co-infection with STIs are common?
- Consider empiric treatment for other STIs
What happens to treatment for some STIs?
It changes over time
Why does the treatment for some STIs change over time?
- Drug availability
- New formulations
What is the purpose of contact tracing?
Patient and public health management
What education should be delivered regarding STIs?
- Sexual health education
- Advice on contraception
- Detailed instruction on practice and need for safer sex
How many types of human papillomaviruses are there?
>100, but small number of particular concern
What kind of virus is HPV?
What % of young adults will experience HPV in their life?
What are the most common types of HPV causing STIs?
HPV 6 and 11
What do HPV 6 and 11 cause?
- Cutaneous, mucosal, and anogenital warts
- Benign, painles, verrucous epithelial or mucosal outgrowths that can be on;
- Perianal skin
- Perianal skin
What are the high risk type of HPV?
16 and 18
What are HPV 16 and 18 associated with?
Cervical (<70%) and anogenital cancer
Why is cervical cancer a major public health concern?
- 2500 cases of cervical cancer in 2012
- Most common cancer in women 15-34
- Large % of cases are potentially preventable
What % of cervical cancers are associated with HPV 16 or 18?
How is a diagnosis of HPV infection made?
- People likely to come forward with warts
- Clinical diagnosis
- Biopsy and genome analysis
- Hybrid capture
What is the purpose of biopsy and genome capture in HPV viruses?
Gives specific nucleic viral section, so can tell if warts are caused by papilloma
How is HPV treated?
- No treatment
- Topical podophyllin
- Intralesional interferon
Why is HPV often given no treatment?
Spontaneous resolution in 70% of cases in 1 year, and 90% in 2 years
How is HPV screened for?
- Cervical Pap smear cytology
- Colposcopy and acetowhite test
- Cervical swab
What does a cervical Pap smear cytology check for?
Early evidence of cervical cancer
What happens in a cervical swab for HPV?
HPV hybrid capture
What % of 20-24 year olds are positive for HPV hybrid capture?
What are the types of HPV vaccine?
What does Cervarix protect against?
HPV 16 and 18
Why is cervarix no longer used in the UK?
There was a large backlash against decision to just protect against 2 HPV types when could protect against more
What does Gardasil protect against?
HPV 6, 11, 16, and 18
When was Gardasil introduced in the UK?
Who is the Gardasil vaccine offered to?
How many doses of Gardasil are given?
How effective is Gardasil?
99% effective in preventing HPV 16 and 18 related cervical abnormaltiies in those not already infected
What is the most commonly detected STI?
What kind of pathogen is C. Trachomatis?
An obligate intracellular bacterium
What is the diagnostic result of C. Trachomatis being an obligate intracellular bacterium?
- Can't grow on gram stains
- Can't grow on agar media
What serotypes of C. Trachomatis cause non-specific genital chlamydial infections?
What are different serotypes of C. Trachomatis associated with?
What does C. Trachomatis infection cause in males?
What does C. Trachomatis infection cause in females?
What is salpingitis?
Inflammation of the fallopian tubes
What are the symptoms of salpingitis?
Abdominal pain and referred shoulder pain from the liver
What does ocular inoculation of C. Trachomatis cause?
What does neonatal infection of C. Trachomatis cause?
- Inclusion conjunctivitis
How is a C. Trachomatis infection diagnosed?
- Endocervical and urethral swabs
- 1st void urine
What is performed on samples taken for investigation of C. Trachomatis infection?
Nucleic acid amplification tests
How is a neonatal infection if C. Trachomatis detected?
Conjunctival swab, followed by nucleic acid amplification tests
How is a C. Trachomatis infection treated?
- Doxycycline or azithromycin, can be given as a single large dose
- Erythromycin in children
Is C. Trachomatis ever asymptomatic?
Yes, many cases are, especially in women
What does the fact that many causes of C. Trachomatis are asymptomatic have implications for?
How many cases of C. Trachomatis are diagnosed each year?
>200,000, nearly half of all STIs
What % of C. Trachomatis cases are diagnosed at GUM clinics?
What % of C. Trachomatis cases are diagnosed from the chlamydia screening programme?
Who does the chlamydia screening programme target?
Sexually active under 25's
How is the chlamydia screening programme carried out?
Urine (M&F) or swab (F), followed by nucleic acid amplification test
What is chlamydia sometimes screened for in conjunction with?
What are the symptoms of primary genital herpes?
- Extensive and painful genital ulceration
- Inguinal lymphadenopathy
What is the inguinal lymphadenopathy caused by in primary genital herpes?
What is primary genital herpes usually associated with?
What does HSV1 usually cause?
How severe is recurrent genital herpes?
Can be asymptomatic to moderate
What allows recurrent genital herpes to occur?
Due to latent infection in dorsal root ganglia
How is a diagnosis of genital herpes made?
PCT of vesicle fluid and/or ulcer base
How is genital herpes treated?
When is aciclovir prophylaxis given?
When a patient has frequent recurrences, to try and reduce frequency and severity
What reduces the risk of transmission of genital herpes?
What kind of pathogen is Neisseria gonorrheae?
Gram negative intracellular diplococcus
What does N. gonorrhoae cause in males?
- Urethritis and painful discharge
- May have referred pain to testes or prostate (felt in perineum)
In whom does N. gonorrhoae cause proctitis and pharyngitis?
What does N. gonorrhoeae cause in women?
What does PID lead to?
Inflammation of the fallopian tubes, which causes them to block and may lead to infertility
What can disseminated gonococcal infection lead to?
- Skin and joint lesions
How is a gonorrhoea diagnosis made?
- Swab from urethra, cervix, throat, or rectum, or urine sample
- Gram stain of pus or normally sterile site
What is the diagnostic difficulty with N. gonorrheae?
Fastidious organism requiring special media
How is gonorrhoea treated?
Why must gonorrhoea be treated with IM ceftrixone?
Due to increasing resistance to many other agents
What is the increasing antibiotic resistance of N. gonorrhoae partially due to?
Movement of strains between different parts of the world, particularly the Middle East
What happens to all patients with gonorrhoea?
They are treated (and tested) for chlamydia with azithromycin
What is the addition benefit of treating gonorrhoea patients with azithromycin for chlamydia?
May prevent emergence of resistance to cephalosporins
What is the aetiological agent of syphilis?
Who are most cases of sphilis found in?
What is the first stage of a syphilis infection?
Indurated, painless ulcer called chancre
What happens to the chancre?
It gradually heals
When does the second stage of a syphilis infection occur?
6 to 8 weeks later
What happens in the second stage of a syphilis infection?
- Mucosal lesions
Describe the rash in stage 2 syphilis?
Can develop anywhere, in any shape/form
Where is the lymphadenopathy in stage 2 syphilis?
Local area around the groin
What is the third stage of syphilis?
Latent, with disease three years
What may syphilis develop into in its final stage?
- Cardiovascular syphilis
What are gummas?
How is congenital syphilis prevented?
Screen pregnant women to ensure that they don't have undetected syphilis that could be passed on to child
What is the problem with diagnosis of syphilis?
Organism can't be grown, apart from in foot pads of various animals, and then must be looked at using dark-field microscopy
How is syphilis diagnosed?
Serology; initial screening with EIA antibody test, and then for people who test positive;
- Rapid Plasma Reagin (RPR) titre
- TP particle agglutination (TPPA)
What is done with the serology of a patient with suspected syphilis?
The serological pattern is interpreted, including false positives and response to treatment
How is syphilis treated?
Pencillin and 'test of cure' follow up to ensure serology is improving
How is syphilis screening conducted?
Detects possibility, then go on to do more specific test
What may inguinal lymphadenopathy be caused by?
- Lymphogranuloma venereum (LGV)
- Chancroid (Haemophilus ducreyi)
- Granuloma inguinale/donovanosis (Klebsiella granulomatis)
What causes LGV?
C. trachoma serotypes L1, L2, L3
What does LGV cause?
Rapidly healing papules (raised lumps) leading to inguinal bubo (abscess)
Where have there been recent clusters on LGV?
Europe, with MSM
What is Chancroid?
Painful genital ulcers
What happens in granuloma inguinale/donovanosis?
Genital nodules leading to ulcers
What kind of pathogen is trichomonas vaginalis?
How is tricomonas vaginalis spread?
Normally by sexual route
What is the relevance of males in trichomonas vaginalis?
They are involved in transmission, but not really affected by it
What does trichomonas vaginalis cause?
What are the symptoms of trichomonas vaginitis?
- Thin, frothy, offensive discharge
- Vaginal inflammation
How is trichomonas vaginitis diagnosed?
Vaginal wet preperation, with or without culture enhancement
How is trichomonas vaginitis treated?
What is vulvovaginal candidiasis caused by?
Candida albicans, or other candida species
Where may candida albicans, or other candida species, come from?
May be part of normal GI and genital tract flora, commonly present in very small numbers
What are the risk factors for vulvovaginal candidiasis?
- Oral contraceptives
What does vuvlovaginal candidiasis cause?
Profuse, white, itchy, curd-like discharge
How is a diagnosis of vulvovaginal candidiasis made?
Usually made by looking at discharge, and based on symptoms, but can also be made by a high vaginal smear, with or without culture
How is vulvovaginal candidiasis treated?
- Topical azoles or nystatin
- Oral fluconazole
What can scabies affect?
How can scabies be spread?
Are pubic lice distinct from other human (body) lice?
What causes bacterial vaginosis?
Pertubed normal flora
Disruption to what normal flora can cause bacterial vaginosis?
What is the disruption of normal flora in bacterial vaginosis usually due to?
Change in pH
What are the symptoms of bacterial vaginosis?
Scanty but offensive fishy discharge
How is a clinical diagnosis of bacterial vaginosis made?
- Vaginal pH >5
- KOH whiff test
How is a laboratory diagnosis of bacterial vaginosis made?
HVS Gram stained smear
What features on a HVS gram stained smear are diagnostic of bacterial vaginosis?
- 'Clue cells'
- Reduced number of lactobacilli
- Absence of pus cells
What are clue cells?
Epithelial cells studded with gram variable coccobacilli
How is bacterial vaginosis treated?